daffodil (n.) 1540s, variant of Middle English affodill "asphodel" (c. 1400), from Medieval Latin affodillus, from Latin asphodelus, from Greek asphodelos, which is of unknown origin. The initial d- is perhaps from merging of the article in Dutch de affodil, the Netherlands being a source for bulbs. First reference to the flower we know by this name (Narcissus pseudo-Narcissus) is from 1590s.

asphodel (n.)late 14c., from Latin asphodelus, from Greek asphodelos "asphodel, king's spear, plant of the lily kind," which is of unknown origin (see daffodil). It was the peculiar plant of the dead; and in Greek mythology and English poetic use it overspreads the Elysian meadows.To embathe In nectared lavers strewed with asphodel. [Milton, "Comus," 1634]